Scaffold



(No Model.)

J. DUNBAR. SGAFFOLD.

No. 482,625. Patented Sept. 13,-1892,

dalfl 00/7607:

UNITED STATns PATENT. OFFICE JOHN DUNBAR, OF BROOKLYN, NEW YORK.

S C A F F O L D SPECIFICATION forming part of Letters Patent No. 482,625, dated September 13, 1892. Application filed March 22, 1892- serial No. 425,909. (No model.)

To all whom it may concern.-

Beit known that 1, JOHN DUNBAR, acitizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Scaffolds; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to whichit appertains to make and use the same.

My invention relates to improvements in scaffolds; and its object is to provide a simple and substantial structure which can be easily unfolded and quickly arranged in position for use or compactly folded togetherfortransportation and storage, and a further object is to provide means adapted to lock and confine the legs andbraces of the scaffold rigidly in their folded position.

\Vith these and other ends in view the invention consists in a scaffold having a number of supports, each of which has two legs hinged together and struts or braces hinged to said legs and guide and locking-plates pivoted on each leg and having a segmental slot therein concentric with the pivotal point thereof, said slot having a lateral offset, in which works a pin on the strut or brace, and a platform provided with cross-pieces sustained on the supports.

My invention consists, further, of certain details of construction and arrangement of parts, as will be hereinafter more fully described and claimed.

To enable others to more readily understand my invention, I have illustrated the same in the accompanying drawings, in which- Figure 1 is a perspective view of my improved scaifold, showing four supports for the platform. Fig. 2 is a side elevation of two of the supports, showing the cross-pieces arranged below the top of the legs. Fig. 3 is a front elevation of one of the supports in a folded position. Fig. 4 is a detail view of the locking-plate, and Fig is a modified form of plate.

Referring to the drawings, in which like letters of reference denote corresponding parts in all the figures, S designates one of the supports, which are all constructed alike and any number of which may be employed; but I have found four or six supports will be sufficient for all ordinary purposes. Each support comprises two legs a, which are hinged together at a near the upper ends thereof, and above the hinge each leg is recessed, and said recessed legs form a socket a" when the legs are spread at the bottom. A brace B is hinged to each leg at b, so that it can be readily and compactly folded against the leg and opened to support the leg when the scaifold is in position. Pivoted on a pin or screw b on one of the legs above the braces. is a locking-plate O, which is adapted to lock the legs together when the support is folded and hold them in position when the legs are spread apart. This plate 0 has a segmental slot a concentric with its pivotal point, and a lateral offset 0' is provided at one end of said slot. A pin or screw 0 is secured to the other leg about opposite the pin or screw b, and it projects through and works in the slot and offset in the plate 0. By this construction of the plate and arrangement of the pivot and stud the legs are held at the proper distance apart, the pin or screw 0 being in the offset 0, and-wl1en the legs are folded the end D of said plate, which may be used as a handle, is turned upward to a vertical position, and the pin or screw 0" will then be at the other end of the segmental slot, as shown in Fig. 3. In this position the legs will be locked tightly together, the distance between the pivot-pin b and the end of the segmental slot being equivalent to the Width of the two legs, so that the pin or screw 0" will hold the legs tightly together when it is in the end of said slot.

In Fig. 5 I have shown a modification of my improved plate, which has a right-angled recess or offset (Z at the end of the slot and another recess or offset (1 at the end of the olfset 0. hen the legs are spread apart, the plate will drop by gravity to bring the pin or screw 0" in the right-angled recess 0, and when the legs are closed and the plate is in the position referred to in Fig. 3 the pin or screw 0 will fit in the recess cl. It will be observed that when the pins are fitting in these rightangled recesses it will be impossible to move the legs, as the plates will obviously lock them rigidlyin place. A locking-plate is pivoted on the legs above the braces and on the sides of said legs, the latter to lock the braces.

The cross-pieces of the platform are fitted in the sockets a" of two supports, or they may rest upon pins e, which are passed through two of a series of openings 6 in the legs when it is desired to have a low scaffold. The platform F of any suitable form and construction is placed upon the cross-piece E.

I do not limit myself to any particular material for constructing the improved scaffold.

I am aware that changes in the form and proportion of parts and details of construction of my invention may be made without departing from the spirit or sacrificing the advantages thereof, and I therefore reserve the right to make such changes as fairly fall within the scope of the same.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a scaffold, a support comprising the legs hinged together, the struts or braces hinged to the legs, and the locking-plates adapted to lock the parts together when folded, substantially as described.

2. A support for scaffolds, consisting of the legs hinged together near the upper ends, the struts or braces hinged to the legs, and the locking-plate pivoted on one leg and having a segmental slot therein, and the pin or screw on the other leg projecting through said slot, substantially as and for the purpose described.

3. A support for scaffolds, consisting of the legs hinged together near their upper ends, the struts or braces hinged to said legs, the locking-plate pivoted on one leg and having a segmental slot therein with a lateral offset,

and the pin in the other leg projecting through said slot and offset, substantially as and for the purpose set forth.

4. A support for scaffolds, consisting of the legs hinged together, the plate pivoted on one leg and having a segmental slot with a lateral offset at one end, the pin on the other leg projecting through said slot, the struts or braces hinged to the legs to unfold at an angle there to, and the plates adapted to lock the struts or braces to said legs, substantially as described.

5. A support for scaffolds, comprising the legs hinged together and the struts or braces therefor and thelocking-plates pivoted on said legs and adapted to lock the legs and braces compactly together, substantially as described.

'6. In a support for scaffolds, the legs hinged together, the locking-plate pivoted on one leg and having a segmental slot and lateral offset therein, a pin or screw in the other leg and projecting through the slot in the plate, said plate beingadapted to lock the legs tightly and compactly together when the end with the offset is turned upward, the struts or braces hinged to said lugs, and the lockingplates pivoted on the legs and adapted to lock the struts or braces, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN DUNBAR.

Witnesses:

JULIUS SHIRER, JOHN M. HUGHES. 

